Cotton doffing assembly



Aug. 19, 1958 RADQW ET A 2,847,815

COTTON DOFFING ASSEMBLY Fil ed Sept. 11, 1956 INVENTORS ROBERT S. RADO'WROBERT E.BENNET BY MAM ATTORNEY United States PatentO COTTON DOFFINGASSEMBLY Robert S. Radow and Robert E. 'Bennet, Dayton, Ohio, assignorsto The Dayton Rubber Company, Dayton,

Ohio, a corporation of Ohio Application September 11, 1956, Serial No.609,238

13 Claims. 01. 56-41 This invention relates to dotfer assemblies andmore particularly to an improved doffer disc applicable for use inremoving cotton from the picker spindles of cotton picking machines. Theinvention further contemplates an improved method for providing dofferassemblies.

Various constructions have been proposed for doifer assemblies in theprior art, but the doffer discs or plates employed to date have beenrelatively inflexible and subject to cracking and splitting. The pickerspindles of cotton machines generally have varying accumulations ofcotton thereon and it is recognized that a balanced uniform engagingrelation between the picker spindles and doffer lugs on the discelements is practically impossible. Accordingly, as the doifer disc unitis applied to the spindles, the doffer lugs thereon are subjected tovarying loads as they are met with the varying accumulations on thespindles. These varying loads on the doifer pads or lugs have repeatedlycaused not only rapid disc deteriora tion from shock effects but alsohave resulted in the dotfer pads being torn from the disc portion inmany instances. This is due mainly to the resistance of the relativelyinflexible disc and poor methods of connecting the disc and doffer lugs.Efforts to correct these difficulties have been made by providing dofferpads of a flexible nature on a metal backed or a hard rubber disc base.However, this has not proved to be the solution to the problem since themanner of fabricating such doffer assemblies has still rendered thedoffer pads subject to being stripped from the doffer disc when heavyloads are applied, a frequent occurrence when using the doffer assembly.

The subject invention oifers a solution to the above problems andprovides a doffer assembly of an improved nature that incorporates thedoffer pads in such manner as to prevent them from breaking away fromthe doffer disc irrespective of the load or of theload variation on thepads as they are applied to cotton picking spindles of cotton pickingmachines. The invention in particular affords a flexible, yet strongdolfer disc unit of a composite nature having doifer pads integrallymolded thereto and connected in circumferentially spaced relation on oneface thereof in a manner that affords greater flexibility to the dofferpad with increased strength and resistance to load thereon. Both thepads and the disc assembly are flexible while being sufficiently strongto .resist any permanent deformation or distortion thereof in use.Increased flexibility with corresponding increased strength of thedotfer assembly thus provided insures against cracking and tearing ofthe dotfer assembly in its various component parts. The doifer assemblyis completely integral in accordance with the invention.

An object of the invention is to provide a new and improved dofferassembly.

Another object of the invention is to provide the improved method offabricating doifer assemblies.

A further object of the invention isto provide an improved doiferassembly wherein both the doffer disc and the doifer pads are of aflexible nature so that they may i each accommodate a portion of theload applied to the dofter pads and protect the pads and the dolferassembly against damage thereby.

Another object of the invention is to provide a novel method of moldingdoffer pads into a doifer disc so as to provide increased strength,stability and life to the dofler pads in use.

Another object. of the invention is to provide an improved method offabricating dolfer assemblies of rubber and rubberized fabric to preventcracking therebetween.

A further object of the invention is to provide an improved disc unitfor a doifer assembly.

Another object of the invention is to provide a doffer assembly andmethod for making the same possessing the advantageous structuralfeatures, the inherent meritorious characteristics, and the improvedmode of operation described herein.

With these and other objects more fully described in the specification,the invention consists of the features of construction, the parts andcombinations thereof, and the mode of operation and method offabrication as hereinafter described or illustrated in the accompanyingdrawings or their equivalents. The above objects are carried out byproviding a doffer disc assembly in which the disc is a sandwich offlexible rubber with a fabric layer on each face, and flexible padintegral with one face of the disc.

* Referring to the drawings wherein is found the preferred but notnecessarily the only form of embodiment of the invention:

Fig. 1 is a perspective view of the doffer assembly according to theinvention.

Fig. 2 is a plan view of the assembly.

Fig. 3 is a cross-sectional view of the assembly of Fig. 2 taken alongline 3-3 thereof.

Fig. 4 is an enlarged cross-sectional view taken on line 4-4 of Fig. 2.

Fig. 5 is an elevational view, with parts broken away and shown insection, illustrating the molding of the doffer assembly.

Fig. 6 is a cross-sectional view, similar to Fig. 4, of a modificationof the doifer assembly of Figs. 1-4.

Referring now to the drawings, the doffer assembly 10 includes anannular disc 11 having a central, aperture 12 and a cylindrical hub 13integral with the disc. The hub has an upwardly projecting portion14 anda downwardly projecting portion 15 which is shorter. The hub ispreferably toothed to provide driving means, but this feature forms nopart of the invention. Surmounting the face of the disc are a pluralityof lugs or dofl'er pads 16 which are integrally connected to the disc 11and have a circumferentially spaced relationship. The lugs are locatedcoextensively with the outer surface of the disc at its periphery andare essentially rectangular in cross-section except for a beveledshoulder 17 at the upper and inner edge. The lugs are preferably made ofa rubber or synthetic rubber material which is fairly hard, yetresilient enough to yield when struck. For this purpose it is found thata rating of about 60 Durometer hardness is satisfactory. In contrast tothis material, the basic material of the disc is a medium hard naturalor synthetic rubber of about 95.Durometer hardness which is fairlyrigid, yet flexible enough to withstand the shock. The disc is thereforeless flexible than the lugs, yet more flexible than metal discs of theprior art. It is this critical relationship between the hard, yetflexible disc, and the more flexible pads that contributes so highly tothe desirable results attained.

The disc is further strengthened by means of two fabric rings 18 and 19,as best shown in Figs. 3 and 4. The rings are composed of a woven fabricmade of natural fibers such as cotton, artificial fibers such as nylon,rayon,

or dacron, or any combination thereof. One particularly effective fabrichas been made by using a nyloncotton combination. The fabric is alsopreferably coated with a natural or artificial rubber to provide abetter seal with the disc. periphery of the disc and extend partiallyinward thereof, but do not extend to the inner periphery thereof toeliminate the possibility of cracking at the hub. The upper ring 18extends further toward the center than does ring 19 in order to minimizecracking at their inner surfaces.

The bonded relationship of the disc 11, the fabric rings 18 and 19, andthe lugs 16 is better understood with reference to Fig. in which themolding apparatus is illustrated. A lower mold 20 has a central apertureand is shaped at 21 to accommodate the upper portion 14 of the hub 13 atits inner portion. The mold is also shaped at 22 to receive each of thelugs 16 at its outer periphery as shown. As can be seen, the mold isdesigned to form the doffer assembly in an upside-down position, inorder that the lugs may be held in place. The lugs are then placed inthe space 22 of the mold and the hub 13 is placed in the space 21, andthe upper fabric ring 18 is laid upon the lugs as shown. The disc 11 isthen placed atop the ring 18, with the inner periphery in contact withthe hub, and the lower ring 19 is placed atop the disc. A centralretainer pin 23 is slipped inside the hub to maintain the inner diameterthereof to a close tolerance.

The doifer assembly is now in place, and the upper mold 24 is placedover the assembly. The two molds, it is noted, are not completely closedat this point, being separated by a gap 25 to permit compression. Theinner portion of the mold adjacent its central aperture has a space 26to accommodate the portion 15 of the hub. It is further noted that theinner surface of mold 24 is slightly tapered to provide for a slightlythicker root portion of the disc, thus providing added strength.

Upon completion of the above steps, heat and pressure are applied, aswell known in the art, sufficiently to vulcanize and bond the componentsof the doffer. The gap 25 is closed to permit the mold surfaces to meet,thu's forcing the fabric rings or layers into the disc and causing themto bond' to the opposite surfaces of the disc. At the same time, thedoffer lugs or pads are forced into the fabric ring 18 to form a unitarystructure of the lugs, fabric, and disc. This process is aided by aslight increase in volume of the lugs which causes them to slightlydepress the fabric ring. The line of bonding between each lug and itscontacting fabric portion is inwardly arcuate in a peripheral direction;that is, when viewed from the outer periphery. This is best shown inFig. 4. As a result, the center portion of the disc is actually belowthe upper surface of the disc. This provides for an unusually strongjunction between the lugs and the disc to minimize the separation orcracking that might otherwise occur. Due to the flexible nature of thedisc and fabric reinforcement with the flexible and well-anchored lugs,a highly effective doffer assembly is obtained. The relative flexibilityof the components of the unitary doffer assembly eliminates the need foraccuracy of the location of the lug elements and the need for a criticalrelation of the lug elements to the picker spindles of the cottonpicking machines. If the relative timing of the contact between thedoffer pads or lugs and the cotton picking spindles is off, the strengthof the flexible pad element and the shock absorbing characteristics ofthe disc assembly insures that the load of the picker spindles will beaccommodated without damage or permanent deformation of the dolferassembly and without damage to the spindles. The flexible lugs offer aprimary shock absorbing action while the wholly flexible disc unitprovides a secondary shock absorbing action to minimize load effectsthereon.

To summarize the many advantages of the improved The rings arecoextensive with the outer 4 l dotfer assembly as described withreference to the preferred embodiment herein, the assembly unit asafforded by the invention is highly efiicient, durable and accordinglyeconomical. It will be noted that the disc assembly, even in itsreinforced condition, is flexible and the lug elements are relativelymore flexible. The integral annular fabric rings at either face of thedisc assembly insure a high degree of strength which is exceedinglyadequate for application to spindles of cotton picking machines. Thevariation in width between the fabric rings 18 and 19 is critical sincethis feature has proven by extensive test to avoid any cracking at thelines of bond. The respective lugs in their molded relation to thesandwich assembly providing the composite disc are anchored in a highlyimproved fashion as pointed out. The relative flexibility of all thecomponents of the invention assembly provided will significantly reducethe normal wear of the lug elements and insure a longer life to theassembly thereby.

A modification of the preferred embodiment of the invention is shown inFig. 6 of the drawings. As proposed therein, the assembly consists of adisc 31 and rubberized fabric rings 32 and 33 which are integrallyconnected to the respective faces of the disc in the manner provided inthe preferred embodiment of the invention. However, in this instancelugs 34 are seated on the fabric ring 32 so as to provide a planarconnection therebetween at the outer face of the sandwich disc unit. Thebase of each of the lug elements is provided with fillets 35 moldedintegrally therewith and extending laterally thereof and also moldedwith and seated in integrated fashion to the fabric ring 32 at theworking surface of the disc assembly. While the disc assembly is of thesame composite structure as the preferred embodiment of the invention,the improved anchoring of the lugs is effected by lateral fillets whichafford stabilization of the lugs relative to the flexible reinforceddisc unit as they are integrated to the fabric band. This is in lieu ofthe anchoring effect of the preferred form, achieved by the arcuate moldline of the fabric ring. A

From the above description it will be apparent that there is thusprovided a device of the character described possessing the particularfeatures of advantage before enumerated as desirable, but whichobviously is susceptible of modification in its form, proportions,detail construction and arrangement of parts without departing from theprinciple involved or sacrificing any of its advantages.

While in order to comply with the statute the invention has beendescribed in language more or less specific as to structural features,it is to be understood that the invention is not limited to the specificfeatures shown, but that the means and construction herein disclosedcomprise but a few of the several modes of putting the invention intoeffect. The term rubber as used herein, and especially in the claims, isintended to refer to not only the natural rubbers, but to syntheticrubbers and combinations thereof which are Well-known in the art.

We claim:

1. A doffer assembly comprising a disc of flexible rubber, reinforcingmeans formed integrally with said disc and providing crack retardingmeans therefor, and doffer lugs seated on and having the root portionsthereof molded to said disc through said reinforcing means to provide anon-planar connection therebetween.

2. A doffer assembly including a flexible base element having fabricreinforcing means connected to at least one face thereof and flexibledoffer lugs integral with said fabric reinforcing means to dispose theroot portions thereof at least in partially depressed relation to seatwithin said base element.

3. A doffer assembly including a disc of relatively hard flexiblerubber, flexible rubberized fabric element means connected to at leastone face of said disc, and

doifer lugs integral with said disc through the medium of said fabricelement means.

4. A doffer assembly including a flexible disc of rubber or the like, anannular section of rubberized fabric integrally connected to eachopposed face of said disc, said fabric sections being of diflerentwidths, and doffer lugs connected to said disc through one of saidfabric sections whereby said assembly will be resistant to cracking andtearing of lugs therefrom.

5. A doffer assembly including a base of a flexible nature, a fabriccoating on at least a portion of said base, and doffer lugs bonded tosaid base through said fabric coating.

6. A doffer assembly including a disc, said disc having means providinga partial rubberized fabric coating adjacent its periphery and dofferlugs seated thereon, the base of said lugs being relatively depressedwithin and bonded to said coating.

7. A dofler assembly comprising a molded disc of flexible rubber or thelike, flexible means molded to the surface of said disc at leastadjacent its periphery providing strength therefor in order to preventcracking or deformation, and flexible dofler lugs engaged integrallywith said disc and said strengthening means.

8. A doifer disc comprising a flexible element of annular configurationhaving mounting means integral therewith, an annular member ofrubberized fabric integral with each of the faces of said elementextending inwardly from its periphery, said members being of differentwidth, said element and members constituting a layered disc highlyresistant to cracking and deformation under load.

9. A doffer disc comprising a flexible element of hard rubber, rings offabric molded to the faces of said element and located at the outerperiphery thereof, said rings increasing resistance of said element tocracking and deformation while maintaining its flexibility and doflerlugs having their roots mounted on and bonded to one of said nngs.

10. A dofler disc assembly comprising a flexible element of medium hardrubber, a peripheral ring of fabric molded to one face thereof lendingresistance to cracking and deformation on distortion while maintainingits flexibility, and flexible lugs molded into said element face to bebonded thereto through said ring.

11. A doifer disc assembly comprising a flexible plate element,peripheral rings of fabric molded to opposed faces thereof lendingresistance to cracking and deformation to the plate element ondistortion, and flexible lugs molded into one face of said plate elementto be bonded thereto through said ring on said face, the roots of saidlug being molded in recessed fashion to the outer surface of thecomposite unit to which they are applied.

12. A doffer disc assembly comprising a flexible element of rubber,annular rings of impregnated fabric molded integrally to opposed facesof said element, said rings lending resistance to cracking anddeformation of the element upon distortion While maintaining itsflexibility, and lugs molded into the ring on one face of said element,the root of each lug being non-planar in nature and the central portionthereof seating deeper than the end portions.

13. A doifer disc assembly comprising a flexible disc of rubber, annularrings of impregnated fabric molded integrally to opposite faces of saiddisc, and a plurality of circumfcrentially equally spaced lugs having agreater flexibility than said disc integrally bonded to one of saidrings and the corresponding face of the disc, the portion of said ringbonded to said disc having an inwardly arcuate shape in a peripheraldirection.

References Cited in the file of this patent UNITED STATES PATENTS2,693,071 Parkerton Nov. 2, 1954 2,720,741 Morkoski Oct. 18, 19552,741,891 Knoth Apr. 17, 1956

